Several publications disclose blending of water and fossil fuel, such as diesel. U.S. Pat. No. 5,156,114 describes a method comprising introducing air and aqueous fuel into a fuel introduction system for the engine. The fuel comprises water from about 20 percent to about 80 percent by volume of the total volume of the fuel, and a carbonaceous fuel from ethanol, methanol, gasoline, kerosene fuel, diesel fuel, carbon-containing gaseous or liquid fuel, or mixtures thereof, and introducing and combusting said air/fuel mixture in a combustion chamber or chambers in the presence of a hydrogen producing catalyst to operate the engine.
Common problems associated with blending water with fossil fuel involve for example separation of mixture after mixing as the density of the two components is different. Another problem of mixing water and fossil fuel is the large dimension of water particles in emulsified fuel resulting in the bigger water particles consuming thermal energy for evaporating water. Attempts have been made with injecting pure oxygen together with the fuel, which has caused damaging of fuel injectors, fuel pump and even damaging of engine. Other problems are condensation of water in the cylinder space after running and present water particles in crank case oil, decreased flammable point of fuel, increasing of density of blended fuel, increasing of pressure in fuel delivery system and lubrication of fuel delivery system. These are just some of the problems relating to the quality of the mixture and to the introduction/injection into the engine.